Saving and Restoring View Changes
There is an addon called Stored Views (3D View: Stored Views) which comes with Blender 2.80. This simple extension allows you to save views (location &amp; rotation of viewport). The UI for it is located in the [N] sidebar panel under View -> Stored Views.

You can save and name any (?) number of views and quickly restore them by pressing their respective buttons. No cameras required. Although it actually allows you to save the current view as a camera as well.

It is not exactly what I originally asked for (restoring viewport changes), but it is the next best thing. Maybe actually better in terms of workflow.

Hopefully this will help those (like me) who model objects at crazy orientations.